


Extra Credit

by TheBetterQuibbler



Category: Harry Potter - J. K. Rowling, Sherlock (TV)
Genre: Blow Jobs, Classroom Sex, First Kiss, First Time, First Time Blow Jobs, M/M, Shameless Smut, Smut, Teacher-Student Relationship
Language: English
Status: Completed
Published: 2017-02-21
Updated: 2017-02-21
Packaged: 2018-09-26 00:51:26
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,550
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9854696
Author URL: https://archiveofourown.org/users/TheBetterQuibbler/pseuds/TheBetterQuibbler
Summary: John isn't great at potions. In fact, in Professor Holmes's words, John's potion skills are "wretched." So, it seems that John's only hope is getting a little bit of tutoring help from the young potions master... and maybe a bit of extra credit along the way.





	

“Professor Holmes, am I doing this right?” a high, flirtatious voice asked from across the room. John looked up to see Janine Hawkins, a Ravenclaw and a fellow seventh year, practically batting her eyelashes at the young potions master. The man, as usual, seemed impervious—and possibly somewhat ignorant—to her advances as he walked over and looked into her simmering cauldron, a single eyebrow arched.

 

“It appears so, Miss Hawkins,” the professor answered, his tone somewhat bored. It seemed that he was just as unsurprised as John was that her potion was perfect. After all, she was the best in their class, much to John’s agitation. It probably wouldn’t have bothered John as much if she would just own up to being the best, but instead she used it as an excuse to come on to Professor Holmes, acting all modest while simultaneously impressing him with her skill. If the professor were a normal man, her attempts at seducing him might have actually worked. But from what John had observed in the two years that the man had been the potions master here at Hogwarts, the professor wasn’t and would never be attracted to anybody, much less a student.

 

“Would you mind watching for a bit to make sure that I don’t do anything wrong?” Janine insisted, and then, from the opposite side of the room, another voice spoke up:

 

“God, Janine, can you keep it in your pants for one bloody day?”

 

This came from Irene Adler, a Slytherin, and John had to admit that he was glad someone had finally said it. The irony was that Irene had a reputation for doing exactly what she was telling Janine to _stop_ doing. Although, to her credit, she never did it with teachers.

 

“Excuse me? Did the Whore of Babylon just tell me to ‘keep it in my pants’?” Janine had stood up and was glaring at Irene, who wasn’t even bothering to glower back. Instead, she remained focused on her own potion, which, John noted, looked almost as good as Janine’s.

 

“Yeah, she did. That’s got to be embarrassing, doesn’t it?” Irene retorted.

 

It appeared as though a full-blown catfight was about to break out…

 

And then John’s potion exploded.

 

He had been so distracted by the two girls that he hadn’t been paying attention to how long his concoction had been boiling. The instructions said to only let it boil for three minutes, no more, but he’d forgotten to time it as his head had been whipping back and forth as though he’d been watching a ping-pong match. Because of this, a puff of grey smoke had erupted from the opening of the cauldron, followed by the smell of burnt asparagus and a foamy, acidic substance that immediately began eating its way through the desk the cauldron was sitting on.

 

“Ah!” John shouted out in surprise, pushing away from the mess he’d made and fearfully pulling his wand out of the pocket of his robes, as if he knew what to do to stop the acidic foam from eating away at everything it touched.

 

Professor Holmes was by his side in a flash, wand at the ready, and in a matter of moments the foam was gone, the smoke had cleared, and everything was back to normal—aside from the lingering scent of burnt asparagus and the hole in the desk. Everyone was staring at John with wide eyes, the catfight all but forgotten, and John felt his face flush red in embarrassment. Of course this would happen to him. That just seemed to be how this year was going. If he kept this up, there was no way he’d be accepted into St. Mungo’s apprentice program once he graduated ( _if_ he graduated).

 

“Mr. Watson,” the professor said sharply, and John winced. “I’d like to speak with you after class.”

 

Welp, there it was. John was about to be kicked out of Professor Holmes’s potions class. And without this credit, he could kiss his dreams of becoming a Healer goodbye. Then again, he couldn’t say that he was surprised. He’d barely scraped by with an ‘E’ in the potions section of his OWLs, and Professor Lestrade had to convince Professor Holmes to let him into the class because man normally only took students that received an ‘O.’

 

John sat on his stool miserably for the rest of the class period as his peers finished up their potions—they were meant to be making a Drought of Living Death. He watched as the professor went around to each cauldron and gave them a grade for their concoctions, and he felt like doing himself in with the killing curse right then and there. Then he waited as all of his classmates filed out of the room, glancing back over their shoulders as they left, giving John sympathetic looks. Only Irene didn’t seem to pity him. Instead, she gave him an oddly suggestive smirk as she left, closing the door behind her, as she was the last one out.

 

John watched as Professor Holmes paced around the dungeon slowly, his hands clasped behind his back, long black robe flowing. His mop of curly brown hair hung down over his thick brown eyebrows, which were, in turn, furrowed over his ever-changing eyes. Just as John was about to shout at the man to stop torturing him and just get on with it, the man turned startlingly fast and marched over to stand in front of where John sat. John stared up at the professor with wide, blue eyes, leaning back a bit on his stool so that he wasn’t craning his neck to look meet the professor’s gaze. Well, he would have met the professor’s gaze, if his gaze had stood still. Instead, it flickered all over the place at lightning speed, from John’s right shoulder to his tie to his pants to his shoes back up to his hand that was clutching his wand and then finally lingering on his lips for a fraction of a second longer than everywhere else before coming up to meet his eyes.

 

“You are absolutely terrible at potion brewing, Mr. Watson.”

 

John blinked twice and then cleared his throat before saying, “Sorry?”

 

“Your comprehension of the text is abysmal at best and you don’t seem to have the attention span necessary to—”

 

“With all due respect, sir,” John interrupted, and the professor looked no less than floored that he was being cut off, “I have a fairly decent comprehension of the text, and my attention span is… well, I think it’s above average. Today was just an unusual circumstance.”

 

“Is that so?” the professor asked drily. “And what, exactly, made it such an unusual circumstance? Two pretty girls getting in a spat? You wish to become a Healer for St. Mungo’s, correct? Are you implying that this will happen every time two women choose to have it out in front of you?”

 

“Well… No… I mean, that’s not what I…” John really didn’t like what the professor was implying. Did he really think that John was shallow enough to only have been distracted because the two having a row were women? “It had nothing to do with—”

 

“To be frank, Mr. Watson, I only let you into this class because Geoffrey was quite insistent that you would be an asset, but so far I’ve found you to be subpar at your most impressive.”

 

John wanted to argue on his own behalf, but instead he found himself asking, “Who’s Geoffrey?”

 

“Geoffrey. Geoffrey Lestrade.” Professor Holmes waved his hand dismissively.

 

“I think his name’s actually _Greg_ , sir.”

 

This tripped the professor up a bit. “What do you mean?”

 

“I mean, I feel pretty positive that Professor Lestrade’s name is actually Greg, sir.”

 

The professor stared at John for a moment, and then shook his head. “No, no, that can’t be right.”

 

John felt pretty confident that he actually was right, but he decided not to get into it with the professor right now when his future career could be on the line.

 

“Sir, about the class. Please, I need it, and I need to pass it. I swear that I take this seriously, but potions just doesn’t come to me as naturally as some of my other classes. I’ve been trying to find a tutor, but nobody has the time. They’ve all got their own NEWTs to worry about, and—”

 

“Do you have a girlfriend, Mr. Watson?”

 

This drew John up short. “Sir?”

 

“Girlfriend, Watson, surely you’ve head of them. Humans of the female variety who—”

 

“Yes, I know what a girlfriend is,” John snapped irritably. “I just don’t understand what that has to do with anything.”

 

“Just answer the question.”

 

John was fighting the urge to storm out then and there, since the professor obviously wasn’t taking this seriously. Instead, he stared the professor down, cocking his head to the side with an unamused smile, and said, “No, I don’t have a girlfriend.”

 

“Boyfriend?”

 

John licked his lips. Suddenly, the professor’s gaze felt like it was searing his flesh, like he was staring right through him. He shifted a bit in his seat. He’d always thought that the professor was an attractive man. After all, someone would have to be blind to _not_ see that. But the professor had always seemed so adverse to people’s sexual advances, and anyway he was a teacher. _And_ , John wasn’t gay, so he didn’t really know why he was having any of these thoughts to begin with.

 

“No boyfriend, no.”

 

“Not your area, or—?”

 

“I never said that.” The words came quick to John’s lips, before he’d even known that he was going to say it. He felt his cheeks flush hot, but he wasn’t sure if it was from embarrassment or the way it looked as though the professor was undressing him with his eyes.

 

“Right…” Professor Holmes watched John carefully for a few more moments before nodding slowly. “Well, I’m very busy. As I’m sure you’ve heard, I work as a consulting Auror for the Ministry. They come to me whenever they’re out of their depth, which is always. The only reason I took this teaching position is because my brother is the Headmaster here—I trust that even you figured that out.”

 

John chose to ignore the stab at his intellect and simply nod, mostly because he was struck dumb by the intensity of the professor’s gaze.

 

“So, between teaching at this godforsaken school and helping the Ministry, I really don’t have time for much else. However, I might be… _persuaded_ to help you in your studies for a small price.”

 

“A—” The word came out as a wheeze, and John cleared his throat before continuing. “A small price?”

 

“I find you intoxicating, Mr. Watson.” The professor hadn’t moved from the spot he’d been planted in since the beginning of their… ‘conversation’ didn’t seem to be the right word for it… but somehow it felt like he was closer to John than ever before. The air was becoming thick and the whole world felt as though it had shrunk down into that small dungeon.

 

“You’re my professor.”

 

“You’re seventeen, correct?”

 

“Yes.”

 

“Then you’re an adult. And I’m only a few years your senior.”

 

John had always suspected that they weren’t far apart in age, but that didn’t change the taboo of what the man was implying.

 

“If anyone found out, you could be fired.”

 

“Are you always this obvious?”

 

This actually made John crack a smile, and the professor mirrored it. They watched each other carefully for a few moments, and John felt heat slowly gathering in the pit of his stomach. Finally, he nodded.

 

“I guess I could use some extra credit.”

 

That seemed to be all of the invitation the professor needed.

 

The man had John’s face between his hands in a matter of seconds, and John jumped to his feet, the stool that he’d been sitting on clattering backwards onto the stone floor. As the professor’s thin lips met John’s soft ones, he had the fleeting thought, _So much for not being gay_. Then his mind emptied as the professor’s lips worked John’s open and his tongue slid into John’s mouth. John gave an involuntary gasp, and the professor took advantage of this, pushing in ever farther. He then backed John up into the edge of the desk and slid a knee between John’s thighs.

 

John had never done this with a man before. Then again, he’d hardly even done this with a girl before. That is, unless he counted that one time in fourth year with Mary Morstan, where they’d made out in some secret passage and she’d let him touch her left breast under the shirt but over the bra. So having another man’s knee firmly planted between his thighs was both exhilarating and intimidating. He wasn’t quite sure what he should be doing. Should he thrust? Or grind? He felt pretty positive that he shouldn’t be staying still, which was the course of action he’d been taking up until this point.

 

The professor drew back from John for a second, barely, his hands still holding John’s face while John’s fists clutched the back of his robe. “I’ve never done this either, you know.”

 

“Really?” John panted, a bit shocked. “You seem very confident about it all.”

 

The professor shrugged, quirking his mouth into an incredibly sexy crooked grin. “I’ve fantasized about this moment. A lot.”

 

This turned John on more than anything else up until this point, and he quickly pulled Professor Holmes back to him with a force that surprised even himself. Their lips met again, and now John let himself go completely, rocking his hips up against the professor’s leg, sending jolts of pleasure down his cock each time he did so. This went on for about a minute, and then suddenly he was shocked to find his arms empty and his lips moving against air. His eyes shot open, and he stared around the empty dungeon, confused for a moment, before he felt the tug at his belt.

 

He looked down and was met with the top of a head of curly hair. The professor’s fingers were making quick work of John’s belt, buttons, and zipper. In a matter of seconds, the man was peeling John’s trousers down, leaving him to stand in his red boxer-briefs, erection straining against the thin material. The professor glanced up at him and cocked a playful eyebrow.

 

“Red? I figured a proud Hufflepuff would avoid Gryffindor colors at all costs?”

 

“I do. Gryffindor is scarlet. My pants are candy apple red.” John had meant this to sound sarcastic and flirtatious, but in the end, with his voice all breathy, it just sounded a bit stupid.

 

“How anyone could mistake you for heterosexual is beyond me,” the professor remarked with a roll of his eyes before leaning forward and kissing the inside of John’s thigh. John groaned and rolled his head back, his cock throbbing in anticipation. He wanted the professor to just get to it, but instead the man made a point to kiss every square inch of John’s lower half except for the part that bloody _mattered_.

 

“Are you always this big of a tease?” John gasped, and the professor chuckled.

 

“I thought we already established that I’m as new to this as you are.”

 

“Well then, hurry it up, because—guhhh….” His smart-arse remark was cut off by the professor suddenly mouthing John’s cock through his pants, and John barely managed to remain standing, clutching at the edge of the desk behind him. “P… Professor…”

 

The professor trailed his fingers under John’s layers of shirts and up his torso before slowly sliding back down. “Sherlock. Call me Sherlock. Please.”

 

John nodded, and tried the name on his tongue. “Sherlock…”

 

The professor—Sherlock—groaned against John, the sound of John saying his name apparently too much for the man. He hooked his thumbs into the elastic of John’s red pants and pulled them down to his ankles, feeing his fully erect cock. The sensation of the cold dungeon air hitting it made John gasp, but the feeling of Sherlock’s tongue trailing up the underside of his shaft was almost too much to bear, and he moaned loudly. He hoped to god that Sherlock had thought to put some form of soundproofing spell of the door, or else somebody might be getting a very fun show.

 

When Sherlock’s mouth finally encircled the head of John’s cock and then slid down almost to the base, it took everything he had to keep from climaxing right then and there. Thankfully, he’d been wanking off for enough years to at least have some stamina. He bit his lip painfully hard to keep from crying out like a girl in a porno, and he twisted his fingers into the professor’s mop of curly hair. He forced himself to stay still, because the urge to fuck Sherlock’s mouth was nearly too strong to resist.

 

He had a hard time believing that this was the man’s first time doing something like this, because it felt too damn good to be the work of a rookie. Sherlock’s head bobbed back and forth with ease while his tongue teased the head of John’s cock with precision. In a matter of minutes, John had essentially lost all control of himself and was moaning and whimpering with each suck and lick. Finally, he couldn’t keep himself from it anymore, and he saw a flash of white as he came in Sherlock’s mouth, crying out “Sherlock!” as he did so. As he came down from the high of the climax, his legs gave out from under him, and he slowly lowered himself to the floor so that he and Sherlock were face-to-face. Sherlock appeared absolutely disheveled, with his curls a frizzy mess and his cheeks flushed and eyes alight. It was absolutely arousing. John watched hungrily as Sherlock wiped the remnants of saliva and ejaculate from the corners of his mouth.

 

John then noticed the erection still straining against the professor’s trousers. He nodded to it and asked, “Do you need me to take care of that?” He wasn’t entirely sure if he was ready to give another man a blowjob, but it felt rude to be sucked off and then not offer the same.

 

The professor—it felt a little weird to call him Sherlock now that they weren’t in the throes of passion—studied John’s face for a moment before shaking his head. He then reached down, unbuckled his own belt, and then tugged his trousers and pants down just enough to set his erection free. Then, without breaking eye contact with John, he began wanking himself off, slowly at first, and then picking up speed and rhythm. It was, by far, the hottest thing John had ever seen—and he’d just watched this same man give him a blowie.

 

Finally, the professor came, his ejaculate spraying out onto John’s right leg, which was splayed ungracefully between himself and the professor. It was hot and sticky, and John felt his cock twitch in arousal. Once the professor had successfully pleasured himself, he leaned forward and gave John a bruising kiss, pressing their lips together so hard that John was sure his would be swollen tomorrow.

 

After they broke apart, the professor quickly tucked himself back in and straightened himself up, ruffling his hair with his hands, causing it to fall back into its usual orderly chaos. It took John a bit longer to pick himself up and put himself together. When he finally managed it, the professor was already hurrying about, tidying up the room and reorganizing the papers on his desk. John slowly walked to the front of the classroom, his legs a bit shaky but otherwise keeping it together.

 

“So, I think that we should plan our tutoring sessions for Saturdays at ten in the morning, if that works with you,” the professor said briskly, not meeting John’s eye.

 

John’s eyebrows shot up. “Ten seems a bit early to be doing… _this_ , don’t you think?”

 

The professor glanced up, cocking his head to the side. “Oh, no, Mr. Watson. Your potion skills are still wretched. We’ll need to do some actual tutoring if you hope to stay in my class.”

 

“Oh,” John said, blushing. “Right. Of course. Yes. Sorry.”

 

The professor studied him for a moment, and then smiled, walking around the front of his desk and catching John’s face between his hands once more. “We’ll just use _this_ as a reward system.”

 

He then pressed a much gentler kiss to John’s lips, softer than any of the others they’d shared in the past half hour. When he pulled away, he stared into John’s eyes for a moment before sighing and stepping back.

 

“Well, I’ve another class coming in soon, and I’m sure you’ve got other commitments as well. So…”

 

John cleared his throat and nodded. “Yeah. Uh, see you ‘round?”

 

“Indeed.”

 

They smiled at each other for a moment longer, and then John turned, grabbed his bag and cauldron off of his desk (which still had a large hole melted through it), and walked out the door, casting one last glance over his shoulder at the professor.

**Author's Note:**

> I hope you all enjoyed my first ever attempt at smut! Hopefully it wasn't too obvious that I'm an amateur, but if it was, please be nice about it! And if you'd like me to possibly make this into a series of one shots, let me know in the comments!


End file.
